JPH0612139B2 - Marine deceleration reversing machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a marine speed reducer / reverse gear driven from a main engine in a ship such as a fishing boat and a leisure boat, and particularly to a propulsion shaft supported by a hull, The present invention relates to a marine speed reducer / reverse gear having a gear device that transmits power by changing a rotation speed from a horizontally arranged main engine.

[Conventional technology]

In order to widely and effectively use the space inside the hull of fishing boats, leisure boats, etc., the main engine is installed near the rear end of the hull, and the propulsion shaft is attached to the bow side of the main engine from a speed reducer / reverser, The structure in which the output shaft, which is inclined downward and protrudes on the same side as the input side, is connected via a joint has been conventionally used.

FIG. 3 shows the configuration, in which the main engine 1 is the hull 2
The main engine 1 is installed at the rear end of the
Are integrally attached, and the output shaft 4 is inclined and projected downward on the same side as the input side so as to be connected to a propulsion shaft 5 which is inclined and provided via a joint.

A special gear is required for the engagement between the inclined output shaft 4 and the other shafts that are axially supported in parallel with each other. In general, for a marine vessel, a conical gear meshes with this conical gear. In addition to conical gears, cylindrical gears are also used as counterpart gears.

Conical gears are also called taper gears, conical gears, etc., and their external shape is similar to bevel gears, but the conical gears are created by a hobbing machine using the same hob as in the case of cylindrical gears. It is made by cutting diagonally along. Therefore, when viewed in the axial direction, the diameter of the gear changes continuously, but because the module and the number of teeth do not change, the tooth profile changes continuously when viewed in the axial direction.
That is, it has an involute tooth surface of a dislocation gear whose dislocation coefficient increases from the small diameter end to the large diameter end.

As described above, since the conical gear is composed of an assembly of dislocation gears with a small width, if the values of the modules of the gears are the same, not only a conical gear with an arbitrary conical angle but also a cylindrical gear is used. It is possible to engage with each other, and further, it is possible to engage not only between the intersecting axes and the parallel axes but also between the interleaving axes.

Further, the conical gear has a particularly good tooth contact when the inclination angle between the shafts is as small as about 10 ° as in the case of use in a marine reduction / reverse gear,
Moreover, bevel gears can be easily cut using the same hobbing machine as when cutting cylindrical gears.Bevel gears with a small inclination angle between shafts like this require a high degree of cutting accuracy. It is the one that is favorably used.

[Problems to be solved]

However, in reality, the conical gear is rarely used except for the transmission of a small amount of power such as a spline such as a shaft coupling and a gear for steering.

In other words, even when it is used for marine vessels, it is limited to some small vessels with small transmitted power and is not widely used.

The reason is that the conical gear is not standardized yet, but theoretically the contact area of the tooth is small and it is locally stressed. Due to the risk of damaging the surface.

That is, the conical gear has a gear diameter that continuously changes in the axial direction, but since the whole is cut with the same gear cutting pitch circle, it has an involute tooth surface with innumerable thin tooth width when viewed in the tooth trace direction. It is possible to mesh with any transition gear having the involute tooth surface of the same module by overlapping the transition gears, but there is no transition or a gap between such continuous transition gears or with such continuous transition gears. Looking at the meshing with the cylindrical gear that has been dislocated, the gears come into contact at the point where the sum of the dislocation coefficients of both gears that mesh is zero, but if they do not become zero, the end of the tooth line whose sum is closest to zero Contact in part.

Conventionally, the position of this point contact is adjusted so that the shift coefficient of both gears meshes so that it comes near the center of the tooth width, the mounting angle of the hob when cutting the gear, or the tooth when cutting. The surface was subjected to crowning to intentionally make contact near the center.

The reason why the conical gear cut in this way causes point contact is that the involute tooth surface in the tooth trace direction has a slightly conical shape.Theoretically, the conical gear has a myriad of minute tooth widths. Dividing into dislocated gears and giving a condition of complete meshing for each dislocated gear pair, the amount of change in inter-axis distance is set at the contact point, that is, the sum of the dislocation coefficients of both meshed dislocated gears (divided) is zero. When the calculation is performed with the point at which is given as a reference, as shown in the example in FIG. 4, the central point c at which the sum of the dislocation coefficients of both gears becomes zero
It can be seen that with reference to, the value increases in a negative value toward both ends a and b in the tooth trace direction. Therefore, the point c at the center makes contact, but the points a and b at both ends do not make contact.

In the above example, the other meshing gear is a cylindrical gear, but similar results can be obtained when the mating gear is a conical gear.

The present invention has been made in order to solve such a problem, and has a gear reducer / reverse gear having a gear device including a conical gear having a large tooth contact area and capable of transmitting a large amount of power without risk of tooth surface damage. Is intended to provide.

[Means for Solving Problems] In order to solve the above problems, the present invention changes the rotational speed of a horizontally arranged main engine to a propulsion shaft tilted and supported by a hull to supply power. In a marine speed reducer / reverse gear having a gear device for transmitting, at least one gear of the gear device, such as an input shaft and an output shaft, which is engaged with a gear pair fixed to non-parallel shafts, is a conical gear,
Further, at least one of the gears is a gear in which the tooth traces of the involute tooth surface are arcuately depressed.

It is to be noted that the tooth flank of the involute tooth surface of the conical gear has an arcuate depression shape from the large diameter side to the small diameter side.
As shown in the figure, by using a hobbing machine, the shape is given to the template that indicates the cutting angle and the depth of the hob. Fig. 6 (b) shows the shape of a template that gives an arcuate depression to the tooth flank of the tooth surface. It is a feeler that works in conjunction with the movement of the hob that cuts gears. Arc-shaped recessed tooth trace processing is performed by tracing the contoured surface 6.

The shape of the arcuate concave tooth line is determined by the curved surface of the template (b) (the size of which is given by the radius as an arc) and its mounting angle.

FIG. 6 (a) shows a conventional template. Since the profile surface 7 is flat, the hob only moves diagonally and straightly to make the tooth flanks of the involute tooth surface into an arcuate concave shape. Cannot be processed.

Factors for designing the shape of the template for giving this arc-shaped recessed tooth line are many such as the number of teeth, module, axial crossing angle, tooth pressure angle, dislocation coefficient, helix angle, and tooth width. Since it is impossible to obtain actual measurement values for all of them because the combined numerical value changes, it is not worthwhile to calculate, so design calculation is performed only for the first necessary case, and with reference to it, tooth contact By finishing the shape of the template while confirming the above, better tooth contact can be obtained, and in the case of the same case, this template can be effectively used as it is. When using a hobbing machine with a combination of NC devices, instead of using a template, the dimensions of the arc-shaped recessed tooth line machining are automatically entered by directly inputting numerical values, and template processing is omitted. Therefore, it is particularly efficient when the processing is sequentially performed as described above. FIG. 7 shows the difference between the normal tooth surface of a conical gear (two-dot chain line) and the tooth surface of an arc-shaped depression (solid line).

[Action]

In a gear device of a marine reduction / reverse gear, for example, an input shaft and an output shaft, at least one gear of a gear pair fixedly engaged with non-parallel shafts, and a conical gear,
Also, since at least one gear is a gear with its involute tooth flanks having an arcuate concave shape, the meshing of the gears changes from point contact to line contact, and the gear teeth have a wide contact area in the tooth trace direction. Can be stressed,
Large power transmission is possible between the conical gear that meshes with the cylindrical gear and the conical gear that meshes with the conical gear. Therefore,
An inexpensive deceleration and reversing machine that uses a conical gear that is easy to manufacture,
It can be applied to large vessels in combination with a large horsepower main engine.

〔Example〕

FIG. 1 shows a first embodiment of a marine reduction / reversing machine to which a conical gear whose involute tooth flank has an arcuate concave shape is applied.
A hydraulic multi-plate clutch (forward clutch) 11 for forward rotation is connected to the input shaft 10 connected to the drive shaft, and a reverse-rotation hydraulic multi-plate clutch is mounted on a reverse shaft 14 integrated with a driven gear 13 that meshes with a drive gear 12 integrated with the input shaft 10. Clutch (reverse rotation clutch) 15 is provided respectively, and clutch 11
A clutch piston (17) that slides in the axial direction is inserted into the clutch carrier (16) on the input side of 15 and 15, and a pressing force is applied by pressure oil supplied from a hydraulic source (not shown) through a switching valve, Input side clutch plate (18) spline-fitted in the inner circumference of the clutch carrier (16) so that it can slide axially.
And a clutch plate (20) on the output side, which is spline-fitted so as to be slidable in the axial direction, is engaged with the outer peripheral portion of a hub (19) rotatably supported by the reverse rotation shaft 14, and the forward rotation clutch 11 and the reverse rotation clutch. Forward rotation pinion 21 and reverse rotation pinion 22 on each output side of 15
Is engaged with a large gear 27 that is integral with an output shaft 26 that is connected to a propulsion shaft 24 that drives a propeller 23 via a joint 25.

In the reduction / reverse rotation machine 8, the input shaft 10 and the reverse rotation shaft 14 are parallel to each other, but the output shaft 10 and the output shaft 14 are parallel to each other.
26 is installed tilted. Looking at the three-dimensional structure between the shafts, the output shaft 26 is positioned vertically below the input shaft 10, and the input shaft 10 and the output shaft 26 intersect each other at 28, but the reverse rotation shaft 14 and the output shaft 26. And do not intersect with each other due to the misalignment axis due to the mutual positional relationship. Therefore, the reverse rotation pinion 22 and the large gear 27 are both conical gears, and the forward rotation pinion 21 is a conical gear, and the cylindrical gear can be adopted.

As described above, in the gear device, there are the following three combinations in the use of the gears in which the tooth traces of the involute tooth surface are arcuately recessed as the gears fixed and engaged with the non-parallel shafts. For example, in the gear device shown in FIG. 1, the forward rotation pinion 21 is a normal cylindrical gear, the large gear 27 has an involute tooth flank with an arcuate depression, and the reverse pinion 2 meshes with the large gear 27.
2 also uses the first method in which the tooth flanks of the involute tooth surface are arcuately concave, and the reverse pinion 22 is a normal conical gear, and the large gear 27 that meshes with this has the tooth flanks of the involute tooth surface arcuately concave. The normal rotation pinion 21 meshing with the large gear 27 is a normal cylindrical gear.
The method, and the large gear 27 is an ordinary conical gear, and the forward conical pinion 21 and the conical reverse pinion 22 which mesh with the conical gear are the third in which the tooth traces of their involute tooth surfaces are arcuate depressions. With the method. Although there is no difference in action and effect from the first to third methods, the first method is the most desirable from the viewpoint of management such as inspection and correction of tooth contact. FIG. 2 shows another second embodiment. The input shaft 30, the reverse rotation shaft 31, and the forward rotation clutch of the reduction / reverse gear 29.
32, reverse clutch 33, output shaft 34, etc.
Since it is the same as the case of the above-mentioned first embodiment, the description thereof will be omitted.

A big difference from the first embodiment is that the inclined output shaft 34,
The intermediate shaft 35 is provided between the input shaft 30 and the reverse rotation shaft 31 which are provided in parallel with each other and which are parallel to these shafts 30 and 31. The forward rotation pinion 36 and the reverse rotation pinion 37 on the output side of the forward rotation clutch 32 and the reverse rotation clutch 33 are connected to the intermediate shaft 35.
Mesh with the intermediate gear 38, which is integral with
The pinion 39 integrated with the gear meshes with the output gear 40 integrated with the output shaft 34.

Since the gear meshed with the output large gear 40 integrated with the output shaft 34 that is inclined in this way is only the intermediate pinion 39, in this embodiment, only one of the large gear 40 and the pinion 39 is a conical gear. On the other hand, a cylindrical gear can be applied. As a natural result, by making the tooth trace on the involute tooth surface of either one of the gears an arcuate depression, the tooth surface contact becomes a line contact, which enables transmission of a large amount of power and extends the life of the gear. can do. A conical gear may be applied to the large gear 40 from the viewpoint of checking and correction of tooth contact, and the tooth traces on the involute tooth surface of the large gear may be arcuately concave.

In the two embodiments described above, the output shaft of the speed reducer / reverse gear is taken out in the same direction as the input side, but the main engine may be mounted in the opposite direction so that the output shaft is taken out in the opposite direction to the input side.
It is included in the present invention.

[Advantages of the Invention] In a marine speed reducer / reverser in which the output shaft is inclined in accordance with the inclined propulsion shaft to be connected in order to be directly attached to the main engine and to be compactly assembled into a narrow hull, the inclined output shaft and other Of the involute tooth flanks of either or both gears by using a conical gear for one gear and a conical gear or a cylindrical gear for the other gear so as to mesh between non-parallel shafts. By making the tooth trace arcuately concave, tooth contact changes from conventional point contact to line contact,
Since a load is received in a wide contact area in the tooth trace direction, a large transmission force can be obtained. In addition, since the local stress is not applied, there is no danger of damaging the tooth surface and the service life is extended.

[Brief description of drawings]

FIG. 1 is a first embodiment of a speed reducer / reverse gear for a marine vessel in which a gear in which an arcuate concave shape is formed on a tooth trace of an involute tooth surface of the present invention is applied, and FIG. 2 is a second embodiment of the same. Fig. 3 shows the arrangement of the marine reduction / reverse gear on the hull, Fig. 4 shows the amount of change in the axial distance in the tooth trace direction with a conical gear as an assembly of dislocation gears, and Fig. 5 shows the simple structure of the hobbing machine. Sixth
FIG. 7 shows a template of a hobbing machine, and FIG. 7 shows a tooth profile in which tooth flanks of a tooth surface are formed in an arcuate concave shape.

Claims (1)

[Claims] 1. A marine speed reduction / reversing machine having a gear device for transmitting power by changing a rotation speed from a horizontally arranged main engine to a propulsion shaft tilted and supported by a hull, wherein the gear device, for example, At least one gear of a pair of gears that are fixed and engaged with each other such as an input shaft and an output shaft that are not parallel to each other is a conical gear, and at least one gear has an indented tooth flank with an arc-shaped recess. A gear reduction and reversing machine for a ship, which is characterized by using a gear.